diff options
Diffstat (limited to 'src/corelib/thread')
| -rw-r--r-- | src/corelib/thread/qmutex.cpp | 3 | ||||
| -rw-r--r-- | src/corelib/thread/qreadwritelock.cpp | 3 | ||||
| -rw-r--r-- | src/corelib/thread/qsemaphore.cpp | 1 | ||||
| -rw-r--r-- | src/corelib/thread/qthread.cpp | 2 | ||||
| -rw-r--r-- | src/corelib/thread/qthreadstorage.cpp | 2 | ||||
| -rw-r--r-- | src/corelib/thread/qwaitcondition.qdoc | 187 |
6 files changed, 187 insertions, 11 deletions
diff --git a/src/corelib/thread/qmutex.cpp b/src/corelib/thread/qmutex.cpp index eaa7308..db9a415 100644 --- a/src/corelib/thread/qmutex.cpp +++ b/src/corelib/thread/qmutex.cpp @@ -56,8 +56,6 @@ QT_BEGIN_NAMESPACE \threadsafe \ingroup thread - \ingroup environment - \mainclass The purpose of a QMutex is to protect an object, data structure or section of code so that only one thread can access it at a time @@ -416,7 +414,6 @@ void QMutex::unlock() \threadsafe \ingroup thread - \ingroup environment Locking and unlocking a QMutex in complex functions and statements or in exception handling code is error-prone and diff --git a/src/corelib/thread/qreadwritelock.cpp b/src/corelib/thread/qreadwritelock.cpp index 6db10a0..8ce58e9 100644 --- a/src/corelib/thread/qreadwritelock.cpp +++ b/src/corelib/thread/qreadwritelock.cpp @@ -57,7 +57,6 @@ QT_BEGIN_NAMESPACE \threadsafe \ingroup thread - \ingroup environment A read-write lock is a synchronization tool for protecting resources that can be accessed for reading and writing. This type @@ -441,7 +440,6 @@ void QReadWriteLock::unlock() \threadsafe \ingroup thread - \ingroup environment The purpose of QReadLocker (and QWriteLocker) is to simplify QReadWriteLock locking and unlocking. Locking and unlocking @@ -514,7 +512,6 @@ void QReadWriteLock::unlock() \threadsafe \ingroup thread - \ingroup environment The purpose of QWriteLocker (and QReadLocker is to simplify QReadWriteLock locking and unlocking. Locking and unlocking diff --git a/src/corelib/thread/qsemaphore.cpp b/src/corelib/thread/qsemaphore.cpp index 38e800d..df8036f 100644 --- a/src/corelib/thread/qsemaphore.cpp +++ b/src/corelib/thread/qsemaphore.cpp @@ -54,7 +54,6 @@ QT_BEGIN_NAMESPACE \threadsafe \ingroup thread - \ingroup environment A semaphore is a generalization of a mutex. While a mutex can only be locked once, it's possible to acquire a semaphore diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp index 53ac3c7..b3575d4 100644 --- a/src/corelib/thread/qthread.cpp +++ b/src/corelib/thread/qthread.cpp @@ -199,8 +199,6 @@ void QAdoptedThread::run() \brief The QThread class provides platform-independent threads. \ingroup thread - \ingroup environment - \mainclass A QThread represents a separate thread of control within the program; it shares data with all the other threads within the diff --git a/src/corelib/thread/qthreadstorage.cpp b/src/corelib/thread/qthreadstorage.cpp index 25194f4..ebdcab7 100644 --- a/src/corelib/thread/qthreadstorage.cpp +++ b/src/corelib/thread/qthreadstorage.cpp @@ -189,8 +189,6 @@ void QThreadStorageData::finish(void **p) \threadsafe \ingroup thread - \ingroup environment - \mainclass QThreadStorage is a template class that provides per-thread data storage. diff --git a/src/corelib/thread/qwaitcondition.qdoc b/src/corelib/thread/qwaitcondition.qdoc new file mode 100644 index 0000000..ae2de6c --- /dev/null +++ b/src/corelib/thread/qwaitcondition.qdoc @@ -0,0 +1,187 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at http://qt.nokia.com/contact. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \class QWaitCondition + \brief The QWaitCondition class provides a condition variable for + synchronizing threads. + + \threadsafe + + \ingroup thread + + QWaitCondition allows a thread to tell other threads that some + sort of condition has been met. One or many threads can block + waiting for a QWaitCondition to set a condition with wakeOne() or + wakeAll(). Use wakeOne() to wake one randomly selected condition or + wakeAll() to wake them all. + + For example, let's suppose that we have three tasks that should + be performed whenever the user presses a key. Each task could be + split into a thread, each of which would have a + \l{QThread::run()}{run()} body like this: + + \snippet doc/src/snippets/code/src_corelib_thread_qwaitcondition_unix.cpp 0 + + Here, the \c keyPressed variable is a global variable of type + QWaitCondition. + + A fourth thread would read key presses and wake the other three + threads up every time it receives one, like this: + + \snippet doc/src/snippets/code/src_corelib_thread_qwaitcondition_unix.cpp 1 + + The order in which the three threads are woken up is undefined. + Also, if some of the threads are still in \c do_something() when + the key is pressed, they won't be woken up (since they're not + waiting on the condition variable) and so the task will not be + performed for that key press. This issue can be solved using a + counter and a QMutex to guard it. For example, here's the new + code for the worker threads: + + \snippet doc/src/snippets/code/src_corelib_thread_qwaitcondition_unix.cpp 2 + + Here's the code for the fourth thread: + + \snippet doc/src/snippets/code/src_corelib_thread_qwaitcondition_unix.cpp 3 + + The mutex is necessary because the results of two threads + attempting to change the value of the same variable + simultaneously are unpredictable. + + Wait conditions are a powerful thread synchronization primitive. + The \l{threads/waitconditions}{Wait Conditions} example shows how + to use QWaitCondition as an alternative to QSemaphore for + controlling access to a circular buffer shared by a producer + thread and a consumer thread. + + \sa QMutex, QSemaphore, QThread, {Wait Conditions Example} +*/ + +/*! + \fn QWaitCondition::QWaitCondition() + + Constructs a new wait condition object. +*/ + +/*! + \fn QWaitCondition::~QWaitCondition() + + Destroys the wait condition object. +*/ + +/*! + \fn void QWaitCondition::wakeOne() + + Wakes one thread waiting on the wait condition. The thread that + is woken up depends on the operating system's scheduling + policies, and cannot be controlled or predicted. + + If you want to wake up a specific thread, the solution is + typically to use different wait conditions and have different + threads wait on different conditions. + + \sa wakeAll() +*/ + +/*! + \fn void QWaitCondition::wakeAll() + + Wakes all threads waiting on the wait condition. The order in + which the threads are woken up depends on the operating system's + scheduling policies and cannot be controlled or predicted. + + \sa wakeOne() +*/ + +/*! + \fn bool QWaitCondition::wait(QMutex *mutex, unsigned long time) + + Releases the locked \a mutex and waits on the wait condition. The + \a mutex must be initially locked by the calling thread. If \a + mutex is not in a locked state, this function returns + immediately. If \a mutex is a recursive mutex, this function + returns immediately. The \a mutex will be unlocked, and the + calling thread will block until either of these conditions is met: + + \list + \o Another thread signals it using wakeOne() or wakeAll(). This + function will return true in this case. + \o \a time milliseconds has elapsed. If \a time is \c ULONG_MAX + (the default), then the wait will never timeout (the event + must be signalled). This function will return false if the + wait timed out. + \endlist + + The mutex will be returned to the same locked state. This + function is provided to allow the atomic transition from the + locked state to the wait state. + + \sa wakeOne(), wakeAll() +*/ + +/*! + \fn bool QWaitCondition::wait(QReadWriteLock *readWriteLock, unsigned long time) + \since 4.4 + + Releases the locked \a readWriteLock and waits on the wait + condition. The \a readWriteLock must be initially locked by the + calling thread. If \a readWriteLock is not in a locked state, this + function returns immediately. The \a readWriteLock must not be + locked recursively, otherwise this function will not release the + lock properly. The \a readWriteLock will be unlocked, and the + calling thread will block until either of these conditions is met: + + \list + \o Another thread signals it using wakeOne() or wakeAll(). This + function will return true in this case. + \o \a time milliseconds has elapsed. If \a time is \c ULONG_MAX + (the default), then the wait will never timeout (the event + must be signalled). This function will return false if the + wait timed out. + \endlist + + The \a readWriteLock will be returned to the same locked + state. This function is provided to allow the atomic transition + from the locked state to the wait state. + + \sa wakeOne(), wakeAll() +*/ |